With its ISP business all but dead, AOL has been leveraging its existing Weblogs blog network to try to remake itself as a purely editorial company. Late last year, AOL further confirmed its aspirations in this direction by purchasing Michael Arrington‘s Techcrunch network for $25 million, and now they’re following it with an even bigger acquisition: AOL has just bought the widely read liberal blog site The Huffington Post for an astonishing $315 million.

The acquisition was led by AOL CEO Tim Armstrong, whose attempts at re-inventing AOL as an editorial company primarily driven by advertising revenues have been controversial, with some describing AOL’s new blogging initiatives as being akin to the creation of content sweatshops.

It appears Armstrong met a like mind in Huffington Post co-founder Arianna Huffington, with the New York Times describing their relationship as one in which they were finishing each other’s sentences within minutes of meeting. “It was really amazing how aligned our visions were,” said Huffington.

The acquisition of the Huffington Post will result in a big promotion for Huffington, who is now in charge of the newly formed Huffington Post Media Group, which will hereby be responsible for all of AOL’s editorial content, including popular blogs like Engadget and Techcrunch.

There’s a great deal of concern that AOL — which has historically tried to remain apolitical — will suddenly become left-leaning in nature, but Huffington on her part says that her own partisan political stance won’t affect editorial.

The bigger question, perhaps, is whether or not the deal will do anything to turn around AOL’s fortunes. While the Huffington Post enjoyed its first profitable year in 2010, AOL is closer to being put on life-support than ever, having eliminated almost a third of its staff last year. Can blogs really save AOL? Armstrong seems to be betting that they can, but commentators are already observing that the deal’s a mess.